U.S. patent number 4,062,415 [Application Number 05/734,027] was granted by the patent office on 1977-12-13 for method for weighing a vessel supported by shafts journaled in pressurized bearings.
This patent grant is currently assigned to Koppers Company, Inc.. Invention is credited to A. Leslie Miller.
United States Patent |
4,062,415 |
Miller |
December 13, 1977 |
Method for weighing a vessel supported by shafts journaled in
pressurized bearings
Abstract
The weight of a vessel having trunnion shafts supported by
bearings fitted with pressure pads is determined as a function of
the fluid pressure necessary to raise the shafts a constant
distance and maintain the distance constant.
Inventors: |
Miller; A. Leslie (Pittsburgh,
PA) |
Assignee: |
Koppers Company, Inc.
(Pittsburgh, PA)
|
Family
ID: |
24950043 |
Appl.
No.: |
05/734,027 |
Filed: |
October 20, 1976 |
Current U.S.
Class: |
177/208;
177/DIG.9; 266/78; 177/254; 266/91 |
Current CPC
Class: |
G01G
5/04 (20130101); G01G 21/027 (20130101); Y10S
177/09 (20130101) |
Current International
Class: |
G01G
5/04 (20060101); G01G 21/00 (20060101); G01G
21/02 (20060101); G01G 5/00 (20060101); G01G
005/04 (); C21C 005/50 () |
Field of
Search: |
;177/208,209,254,DIG.9
;266/78,91 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Miller, Jr.; George H.
Attorney, Agent or Firm: Sahr; R. Lawrence Brumback; Oscar
B.
Claims
What is claimed is:
1. A method for measuring the weight of a vessel having shafts
journaled in bearings fitted with fluid-actuated pressure pads
acting on said shafts, wherein the improvement in said method
comprises:
a. pressurizing said pads whereby said shafts raise a distance
above said bearings;
b. measuring the resulting vertical distance of said shafts;
c. controlling the pressure on said pads so that said vertical lift
distance is constant; and
d. measuring the weight of the vessel as a function of the pressure
applied to said source of supply.
2. The invention of claim 1 wherein:
a. measuring the weight of said vessel includes reading said weight
on a digital weight indicator.
3. The invention of claim 1 wherein:
a. measuring the weight of said vessel includes recording said
weight.
4. The invention of claim 1 including the steps of:
a. flowing fluid from a pressurized source of supply to said pads;
and
b. maintaining a controlled pressure on said fluid in said source
of supply.
5. The invention of claim 4 including the steps of:
a. collecting excess fluid exuding from said pads; and
b. flowing said excess fluid to said source of supply.
6. The invention of claim 5 including the steps of:
a. flowing said excess fluid into a reservoir; and
b. pumping said excess fluid from said reservoir to said source of
supply.
7. A method for measuring the weight of a vessel having shafts
journaled in bearings fitted with fluid-actuated pressure pads
acting on said shafts, wherein the improvement in said method
comprises:
a. flowing fluid from a pressurized source of supply to said pads
whereby said shafts raise a distance above said bearings;
b. measuring said distance;
c. collecting excess fluid exuding from said pads;
d. flowing said excess fluid to a reservoir;
e. pumping said excess fluid into said source of supply;
f. maintaining a controlled pressure on said source of supply and
fluid acting on said pads whereby said distance is constant;
and
g. measuring the weight of said vessel as a function of said
pressure applied to said source of supply.
8. The invention of claim 7 wherein:
a. measuring the weight includes recording said weight.
9. The invention of claim 7 wherein:
a. measuring the weight includes reading the weight on a digital
weight indicator.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention relates to steelmaking and particularly to
steelmaking by means of a basic oxygen furnace (BOF), ad more
particularly to a method for weighing, by fluid pressure in an
hydrostatic fluid bearing, the BOF converter for determining
process information.
2. Description of the Prior Art:
The concept of weighing a BOF converter to determine process
information during a blowing cycle is not novel. Accurate
in-process weight variations, measured by clusters of electronic
compression load cells, called sometimes "weighing transducers"
located in the bearing pedestals of a small BOF converter in
British Steel Corporation plant in Llanwern, Wales, is described in
an article in Journal of Metals, July 1974.
U.S. Pat. No. 3,746,328 to J. W. Martt describes a fluid bearing
that is used to support a tiltable metallurgical vessel such as a
BOF converter. Such fluid bearing includes "bearing pads" which are
pressurized by hydraulic fluid. The shafts of the BOF converter are
raised on a pressurized film of oil and the fluid bearing structure
compensates for sag along the axis of the BOF trunnion shafts due
to the weight of the vessel itself and its load. The fluid bearing
structure also compensates for effects of sag during repeatedly
changing load and tilting conditions.
SUMMARY OF THE INVENTION
The invention comprises a method for measuring the weight of a
vessel having shafts journaled in bearings fitted with
fluid-actuated pressure pads acting on said shafts, wherein the pad
as are pressurized and the shafts are raised a distance that is
controllably constant. The weight of the vessel is measured as a
function of the pressure of the fluid acting on the pads.
For a further understanding of the invention and for features and
advantages, reference may be made to the following description and
the drawings which illustrate a preferred embodiment of equipment
which is suitable for practicing the method of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a schematic elevational view of a typical BOF converter
supported on bearings fitted with an embodiment of such equipment;
and
FIG. 2 is a schematic view of a system for accomplishing the
purpose of the invention as applied to one bearing of FIG. 1.
DETAILED DESCRIPTION
Referring to FIG. 1, a typical BOF converter 11 is provided with a
pair of trunnions 13, 15 that are journaled in bearings 17, 19
supported on pedestals 21, 23. FIG. 2 illustrates schematically and
typically a bearing 19; it is understood, of course, that bearing
17 is similar and the system described hereinafter as applied to
bearing 19 is also applicable to bearing 17.
Bearing 19, substantially like bearing 40 that is shown and
described in U.S. Pat. No. 3,746,328, includes a sleeve 25 secured
to the trunnion shaft 15. A bearing body block 27 surrounds the
sleeve 25 and has a plurality of fluid bearing channels 29, 31 in
the lower half of the bearing block 27. Fluid under pressure is
supplied to these channels 29, 31 from an accumulator 33 which is
pressurized by pumps 35, shown as a pair, the pressurizing fluid
flowing in conduit 34 into the accumulator 33. The pressurized
fluid flows from the accumulator 33 in line 37 and passage 39 in
the lower portion of the bearing block 27.
Pressurizing fluid flows from the channels 29, 31 into voids 41, 43
outside the ends of the bearing block 27, and passages 45, 47 in
the bearing shell 19, and conduits 49, 51 convey the pressurizing
fluid to a reservoir 53. As shown in FIG. 2, the pumps 35 draw
pressurizing fluid from the reservoir 53 through conduit 55.
Bearing 19 is provided with a depth gage 57 in the top of the
bearing cap. The depth gage 57 contacts the bearing body portion 27
and rises and falls as the bearing sleeve 25 and trunnion shaft 15
rise and fall. The rise of the gage is indicative of the gap
between the sleeve 25 and the bearing body portion 27.
The gage 57 may be part of either a mechanical, electronic or an
optical depth gage sensor 59. The depth gage sensor 59 is
influential of a pressure controller that is, in turn, influential
of a pressure controller 61. The pressure controller 61 acts on a
flow control valve 63 in a fluid line 65, carrying a gaseous fluid
uner pressure that may be as high as 4500 psig. The fluid line 65
is connected to the accumulator 33 and maintains enough pressure on
pressurizing fluid 65 therein.
Accumulator 33 is fitted with an exhaust conduit 67 in which a flow
control valve 69 is situated, such valve 69 being influenced by the
pressure controller 61, as shown. The conduit 67 exhausts the
pressurizing gaseous fluid in the accumulator to atmosphere.
Accumulator 33 is also fitted with a pressure transmitter 71 that
is connected operatively to a weight recorder 73 and a digital
weight indicator 75.
As for the depth gage 57 and sensor 59, they may be a micrometer
type depth gage, insertion type strain gage, a built-in
pressductor, a pneumatic, hydraulic, mechanical, or optical device
capable of measuring accurately to one thousandth (0.001) of an
inch. Those skilled in the art will know of such types of units and
can select a suitable unit from those available in the market
place.
In operation, pressurized fluid, usually a lubricating hydraulic
fluid, is supplied to the channels 29, 31 from the accumulator 33
and the pressurized hydraulic fluid raises the sleeve 25 and
trunnion shaft 15. The distance the shaft is raised is a specified
and controllable distance, being controlled by regulating the
pressure of the hydraulic fluid in the system.
The pressure of the gaseous fluid in the accumulator determines the
pressure of the hydraulic fluid in the system and acting on the
sleeve to raise it.
The pressure of the gaseous fluid in the accumulator is regulated
in response to signals from the depth gage sensor acting on the
pressure controller.
If a constant gap is maintained in the bearing, the total weight on
the bearing then is directly proportional to the fluid pressure
required to maintain that gap. The fluid pressure divided by the
unchanging supporting surface area, provides a direct reading of
the weight on the bearing. The weight is read from the weight
recorder and the digital weight indicator.
Thus, a change in weight of the vessel (the weight on both
bearings) and/or contents is accompanied by a corresponding change
in the fluid supporting pressure.
From the foregoing description of one embodiment of the invention,
those skilled in the art should recognize many important features
and advantages of it, among wich the following are particularly
significant:
That even small changes in weight, such as the carbon loss during a
blowing period, of a BOF can be accurately measured by the method
of the present invention;
That the method of the present invention automatically maintains
the fluid gap between the seat and the trunnion shaft a controlled
distance, and with a constant gap distance the total weight on the
bearing is measured as in dirent proportion to the fluid pressure
required to maintain the constant gap distance; and
That the method of the present invention is simple, accurate and
effective in measuring even the losses in weight of carbon in the
metal during a blowing cycle.
Although the invention has been described herein with a certain
degree of particularity it is understood that the present
disclosure has been made only as an example and that the scope of
the invention is defined by what is hereinafter claimed.
* * * * *